/*******************************************************************************
 * Copyright 2011, 2012 Chris Banes.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/

package com.sfdlJPush.widget.pulltorefresh;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.ListAdapter;

import com.sfdlJPush.R;
import com.sfdlJPush.widget.pulltorefresh.internal.EmptyViewMethodAccessor;
import com.sfdlJPush.widget.pulltorefresh.internal.IndicatorLayout;

public abstract class PullToRefreshAdapterViewBase<T extends AbsListView> extends PullToRefreshBase<T> implements OnScrollListener
{
    private static FrameLayout.LayoutParams convertEmptyViewLayoutParams(ViewGroup.LayoutParams lp)
    {
        FrameLayout.LayoutParams newLp = null;
        if (null != lp)
        {
            newLp = new FrameLayout.LayoutParams(lp);
            if (lp instanceof LinearLayout.LayoutParams)
            {
                newLp.gravity = ((LinearLayout.LayoutParams) lp).gravity;
            }
            else
            {
                newLp.gravity = Gravity.CENTER;
            }
        }
        return newLp;
    }
    private boolean mLastItemVisible;
    private OnScrollListener mOnScrollListener;
    private OnLastItemVisibleListener mOnLastItemVisibleListener;
    private View mEmptyView;
    private IndicatorLayout mIndicatorIvTop;
    private IndicatorLayout mIndicatorIvBottom;
    private boolean mShowIndicator;
    private boolean mScrollEmptyView = true;

    public PullToRefreshAdapterViewBase(Context context)
    {
        super(context);
        mRefreshableView.setOnScrollListener(this);
    }

    public PullToRefreshAdapterViewBase(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        mRefreshableView.setOnScrollListener(this);
    }

    public PullToRefreshAdapterViewBase(Context context, Mode mode)
    {
        super(context, mode);
        mRefreshableView.setOnScrollListener(this);
    }

    public PullToRefreshAdapterViewBase(Context context, Mode mode, AnimationStyle animStyle)
    {
        super(context, mode, animStyle);
        mRefreshableView.setOnScrollListener(this);
    }

    /**
     * Gets whether an indicator graphic should be displayed when the View is in
     * a state where a Pull-to-Refresh can happen. An example of this state is
     * when the Adapter View is scrolled to the top and the mode is set to
     * {@link Mode#PULL_FROM_START}. The default value is <var>true</var> if
     * {@link PullToRefreshBase#isPullToRefreshOverScrollEnabled()
     * isPullToRefreshOverScrollEnabled()} returns false.
     * 
     * @return true if the indicators will be shown
     */
    public boolean getShowIndicator()
    {
        return mShowIndicator;
    }

    public final void onScroll(final AbsListView view , final int firstVisibleItem , final int visibleItemCount , final int totalItemCount)
    {
        if (DEBUG)
        {
            Log.d(LOG_TAG, "First Visible: " + firstVisibleItem + ". Visible Count: " + visibleItemCount + ". Total Items:" + totalItemCount);
        }
        /**
         * Set whether the Last Item is Visible. lastVisibleItemIndex is a
         * zero-based index, so we minus one totalItemCount to check
         */
        if (null != mOnLastItemVisibleListener)
        {
            mLastItemVisible = (totalItemCount > 0) && (firstVisibleItem + visibleItemCount >= totalItemCount - 1);
        }
        // If we're showing the indicator, check positions...
        if (getShowIndicatorInternal())
        {
            updateIndicatorViewsVisibility();
        }
        // Finally call OnScrollListener if we have one
        if (null != mOnScrollListener)
        {
            mOnScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
        }
    }

    public final void onScrollStateChanged(final AbsListView view , final int state)
    {
        /**
         * Check that the scrolling has stopped, and that the last item is
         * visible.
         */
        if (state == OnScrollListener.SCROLL_STATE_IDLE && null != mOnLastItemVisibleListener && mLastItemVisible)
        {
            mOnLastItemVisibleListener.onLastItemVisible();
        }
        if (null != mOnScrollListener)
        {
            mOnScrollListener.onScrollStateChanged(view, state);
        }
    }

    /**
     * Pass-through method for {@link PullToRefreshBase#getRefreshableView()
     * getRefreshableView()}.
     * {@link AdapterView#setAdapter(android.widget.Adapter)}
     * setAdapter(adapter)}. This is just for convenience!
     * 
     * @param adapter
     *            - Adapter to set
     */
    public void setAdapter(ListAdapter adapter)
    {
        ((AdapterView<ListAdapter>) mRefreshableView).setAdapter(adapter);
    }

    /**
     * Sets the Empty View to be used by the Adapter View.
     * <p/>
     * We need it handle it ourselves so that we can Pull-to-Refresh when the
     * Empty View is shown.
     * <p/>
     * Please note, you do <strong>not</strong> usually need to call this method
     * yourself. Calling setEmptyView on the AdapterView will automatically call
     * this method and set everything up. This includes when the Android
     * Framework automatically sets the Empty View based on it's ID.
     * 
     * @param newEmptyView
     *            - Empty View to be used
     */
    public final void setEmptyView(View newEmptyView)
    {
        FrameLayout refreshableViewWrapper = getRefreshableViewWrapper();
        if (null != newEmptyView)
        {
            // New view needs to be clickable so that Android recognizes it as a
            // target for Touch Events
            newEmptyView.setClickable(true);
            ViewParent newEmptyViewParent = newEmptyView.getParent();
            if (null != newEmptyViewParent && newEmptyViewParent instanceof ViewGroup)
            {
                ((ViewGroup) newEmptyViewParent).removeView(newEmptyView);
            }
            // We need to convert any LayoutParams so that it works in our
            // FrameLayout
            FrameLayout.LayoutParams lp = convertEmptyViewLayoutParams(newEmptyView.getLayoutParams());
            if (null != lp)
            {
                refreshableViewWrapper.addView(newEmptyView, lp);
            }
            else
            {
                refreshableViewWrapper.addView(newEmptyView);
            }
        }
        if (mRefreshableView instanceof EmptyViewMethodAccessor)
        {
            ((EmptyViewMethodAccessor) mRefreshableView).setEmptyViewInternal(newEmptyView);
        }
        else
        {
            mRefreshableView.setEmptyView(newEmptyView);
        }
        mEmptyView = newEmptyView;
    }

    /**
     * Pass-through method for {@link PullToRefreshBase#getRefreshableView()
     * getRefreshableView()}.
     * {@link AdapterView#setOnItemClickListener(OnItemClickListener)
     * setOnItemClickListener(listener)}. This is just for convenience!
     * 
     * @param listener
     *            - OnItemClickListener to use
     */
    public void setOnItemClickListener(OnItemClickListener listener)
    {
        mRefreshableView.setOnItemClickListener(listener);
    }

    public final void setOnLastItemVisibleListener(OnLastItemVisibleListener listener)
    {
        mOnLastItemVisibleListener = listener;
    }

    public final void setOnScrollListener(OnScrollListener listener)
    {
        mOnScrollListener = listener;
    }

    public final void setScrollEmptyView(boolean doScroll)
    {
        mScrollEmptyView = doScroll;
    }

    /**
     * Sets whether an indicator graphic should be displayed when the View is in
     * a state where a Pull-to-Refresh can happen. An example of this state is
     * when the Adapter View is scrolled to the top and the mode is set to
     * {@link Mode#PULL_FROM_START}
     * 
     * @param showIndicator
     *            - true if the indicators should be shown.
     */
    public void setShowIndicator(boolean showIndicator)
    {
        mShowIndicator = showIndicator;
        if (getShowIndicatorInternal())
        {
            // If we're set to Show Indicator, add/update them
            addIndicatorViews();
        }
        else
        {
            // If not, then remove then
            removeIndicatorViews();
        }
    };

    @Override
    protected void onPullToRefresh()
    {
        super.onPullToRefresh();
        if (getShowIndicatorInternal())
        {
            switch (getCurrentMode())
            {
                case PULL_FROM_END:
                    mIndicatorIvBottom.pullToRefresh();
                    break;
                case PULL_FROM_START:
                    mIndicatorIvTop.pullToRefresh();
                    break;
                default:
                    // NO-OP
                    break;
            }
        }
    }

    protected void onRefreshing(boolean doScroll)
    {
        super.onRefreshing(doScroll);
        if (getShowIndicatorInternal())
        {
            updateIndicatorViewsVisibility();
        }
    }

    @Override
    protected void onReleaseToRefresh()
    {
        super.onReleaseToRefresh();
        if (getShowIndicatorInternal())
        {
            switch (getCurrentMode())
            {
                case PULL_FROM_END:
                    mIndicatorIvBottom.releaseToRefresh();
                    break;
                case PULL_FROM_START:
                    mIndicatorIvTop.releaseToRefresh();
                    break;
                default:
                    // NO-OP
                    break;
            }
        }
    }

    @Override
    protected void onReset()
    {
        super.onReset();
        if (getShowIndicatorInternal())
        {
            updateIndicatorViewsVisibility();
        }
    }

    @Override
    protected void handleStyledAttributes(TypedArray a)
    {
        // Set Show Indicator to the XML value, or default value
        mShowIndicator = a.getBoolean(R.styleable.PullToRefresh_ptrShowIndicator, !isPullToRefreshOverScrollEnabled());
    }

    protected boolean isReadyForPullStart()
    {
        return isFirstItemVisible();
    }

    protected boolean isReadyForPullEnd()
    {
        return isLastItemVisible();
    }

    @Override
    protected void onScrollChanged(int l , int t , int oldl , int oldt)
    {
        super.onScrollChanged(l, t, oldl, oldt);
        if (null != mEmptyView && !mScrollEmptyView)
        {
            mEmptyView.scrollTo(-l, -t);
        }
    }

    @Override
    protected void updateUIForMode()
    {
        super.updateUIForMode();
        // Check Indicator Views consistent with new Mode
        if (getShowIndicatorInternal())
        {
            addIndicatorViews();
        }
        else
        {
            removeIndicatorViews();
        }
    }

    private void addIndicatorViews()
    {
        Mode mode = getMode();
        FrameLayout refreshableViewWrapper = getRefreshableViewWrapper();
        if (mode.showHeaderLoadingLayout() && null == mIndicatorIvTop)
        {
            // If the mode can pull down, and we don't have one set already
            mIndicatorIvTop = new IndicatorLayout(getContext(), Mode.PULL_FROM_START);
            FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            params.rightMargin = getResources().getDimensionPixelSize(R.dimen.indicator_right_padding);
            params.gravity = Gravity.TOP | Gravity.RIGHT;
            refreshableViewWrapper.addView(mIndicatorIvTop, params);
        }
        else if (!mode.showHeaderLoadingLayout() && null != mIndicatorIvTop)
        {
            // If we can't pull down, but have a View then remove it
            refreshableViewWrapper.removeView(mIndicatorIvTop);
            mIndicatorIvTop = null;
        }
        if (mode.showFooterLoadingLayout() && null == mIndicatorIvBottom)
        {
            // If the mode can pull down, and we don't have one set already
            mIndicatorIvBottom = new IndicatorLayout(getContext(), Mode.PULL_FROM_END);
            FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            params.rightMargin = getResources().getDimensionPixelSize(R.dimen.indicator_right_padding);
            params.gravity = Gravity.BOTTOM | Gravity.RIGHT;
            refreshableViewWrapper.addView(mIndicatorIvBottom, params);
        }
        else if (!mode.showFooterLoadingLayout() && null != mIndicatorIvBottom)
        {
            // If we can't pull down, but have a View then remove it
            refreshableViewWrapper.removeView(mIndicatorIvBottom);
            mIndicatorIvBottom = null;
        }
    }

    private boolean getShowIndicatorInternal()
    {
        return mShowIndicator && isPullToRefreshEnabled();
    }

    private boolean isFirstItemVisible()
    {
        final Adapter adapter = mRefreshableView.getAdapter();
        if (null == adapter || adapter.isEmpty())
        {
            if (DEBUG)
            {
                Log.d(LOG_TAG, "isFirstItemVisible. Empty View.");
            }
            return true;
        }
        else
        {
            /**
             * This check should really just be:
             * mRefreshableView.getFirstVisiblePosition() == 0, but PtRListView
             * internally use a HeaderView which messes the positions up. For
             * now we'll just add one to account for it and rely on the inner
             * condition which checks getTop().
             */
            if (mRefreshableView.getFirstVisiblePosition() <= 1)
            {
                final View firstVisibleChild = mRefreshableView.getChildAt(0);
                if (firstVisibleChild != null)
                {
                    return firstVisibleChild.getTop() >= mRefreshableView.getTop();
                }
            }
        }
        return false;
    }

    private boolean isLastItemVisible()
    {
        final Adapter adapter = mRefreshableView.getAdapter();
        if (null == adapter || adapter.isEmpty())
        {
            if (DEBUG)
            {
                Log.d(LOG_TAG, "isLastItemVisible. Empty View.");
            }
            return true;
        }
        else
        {
            final int lastItemPosition = mRefreshableView.getCount() - 1;
            final int lastVisiblePosition = mRefreshableView.getLastVisiblePosition();
            if (DEBUG)
            {
                Log.d(LOG_TAG, "isLastItemVisible. Last Item Position: " + lastItemPosition + " Last Visible Pos: " + lastVisiblePosition);
            }
            /**
             * This check should really just be: lastVisiblePosition ==
             * lastItemPosition, but PtRListView internally uses a FooterView
             * which messes the positions up. For me we'll just subtract one to
             * account for it and rely on the inner condition which checks
             * getBottom().
             */
            if (lastVisiblePosition >= lastItemPosition - 1)
            {
                final int childIndex = lastVisiblePosition - mRefreshableView.getFirstVisiblePosition();
                final View lastVisibleChild = mRefreshableView.getChildAt(childIndex);
                if (lastVisibleChild != null)
                {
                    return lastVisibleChild.getBottom() <= mRefreshableView.getBottom();
                }
            }
        }
        return false;
    }

    private void removeIndicatorViews()
    {
        if (null != mIndicatorIvTop)
        {
            getRefreshableViewWrapper().removeView(mIndicatorIvTop);
            mIndicatorIvTop = null;
        }
        if (null != mIndicatorIvBottom)
        {
            getRefreshableViewWrapper().removeView(mIndicatorIvBottom);
            mIndicatorIvBottom = null;
        }
    }

    private void updateIndicatorViewsVisibility()
    {
        if (null != mIndicatorIvTop)
        {
            if (!isRefreshing() && isReadyForPullStart())
            {
                if (!mIndicatorIvTop.isVisible())
                {
                    mIndicatorIvTop.show();
                }
            }
            else
            {
                if (mIndicatorIvTop.isVisible())
                {
                    mIndicatorIvTop.hide();
                }
            }
        }
        if (null != mIndicatorIvBottom)
        {
            if (!isRefreshing() && isReadyForPullEnd())
            {
                if (!mIndicatorIvBottom.isVisible())
                {
                    mIndicatorIvBottom.show();
                }
            }
            else
            {
                if (mIndicatorIvBottom.isVisible())
                {
                    mIndicatorIvBottom.hide();
                }
            }
        }
    }
}
